What are the four basic operation of computer system? Input, Process, Output, Storage

What are the subsystems of computer?

Computer Systems are enabled by many subsystems, namely, the hardware subsystem, the software subsystem, and the network subsystem.

2. What are the two types of software?. Two categories: Operating system software, (system software) - the master controller for all activities that take place within a computerExamples of OS software:Microsoft Windows, Unix, Mac OS. Application software - a set of one or more computer programs that helps a person carry out a task Examples of application software:Microsoft Word Internet Explorer Macromedia Dreamweaver,Adobe Acrobat Reader

What are the four basic operation of computer system? Input, Process, Output, Storage

4. What are the categories of computers? Computers are classified based on their technology, function, physical size, performance and cost. Categories:Personal computers,Handheld computers, Mainframes,Supercomputers

5. Give the example of manual calculating device. Manual calculating devices required the use of hands to move components on the device.The first calculation device, the abacus, was used in China. It involved manually moving beads to do calculations. Abacus used in ancient Rome, Greece, India, China, and Japan. Abacus consists of beads mounted on rods within a rectangular frame. Each bead represents a quantity-1.5.10.50 and so on. John Napier, William Oughtred. Napier invented logarithms and a device for multiplication and vision. (Napiers Bones)

6. Why the mechanical calculating device was different? Give the example. MC were developed as early as 1623 by Schickard. Each of the 10spokes on a gear represented a digit. 1642, Pascal developed the Pascaline,a mechanical device that could be used to perform addition, subtraction,multiplication and division. 1673 Leibniz Calculator . 1822 Babbage proposed Difference Engine

7. How we used the punched cards? Examples of devices Punched cards use holes following a specific pattern to represent the instructions given to the machine or stored data. The idea of storing data and program instructions on punched cards came from the Jacquard loom. It used pasteboard cards with patterns of punched holes to produce mass quantity of fabrics weaved in a variety of patterns. Each punched card represents a pattern and the punched card can be fed through the Jacquard loom to produce weaved fabrics of the pattern repeatedly. Similarly, different program instructions can be stored on separate punched cards, which can be fed through the computing machine repeatedly. Using punched cards, program instructions and data can be stored.

1834: Charles Babbage designed a new general-purpose calculating device, the Analytical Engine, which is the ancestor of modern computers. It included the essential components of present-day computers, which are input, process, storage, and output of data.Babbage's assistant, Augusta Ada King, Countess of Lovelace and daughter of English poet Lord Byron, would create the instruction routines stored on punched cards to tell the machine what to do. Instruction routines used by the computer are known as "computer programs." She is thus the first female computer programmer, and in her honor, the U.S. Defense Department named the programming language ADA. 1890: Herman Hollerith designed an electronic punched card tabulating device that enabled the U.S. Census Bureau to tabulate the 1890 census in six months, which would have otherwise taken more than 7 years. Hollerith’s machine used punched cards to store data instead of instruction routines.

1896: Hollerith thought the business world could benefit from the electronic punched card tabulating device, and founded Tabulating Machine Company, which later became International Business Machines (IBM) in 1924.

8. Why transistors are better than vacuum tubes? Transistors performed functions similar to vacuum tubes but they were smaller, cheaper, and more reliable. Additionally, they consumed less power. The ability for transistors to replace vacuum tubes was first demonstrated in AT&T’s Bell Laboratories. Transistor-based computers could perform 200,000 to 250,000 calculations per second. 1940s—Vacuum Tubes Used to control the flow of electrons. Faster computations were possible. But burned out quickly.

9. What is the difference between data and information? Data is facts and statistics used for analysis, whereas information is knowledge derived from experience or study or instruction. Data must be interpreted whereas information is communicated. Data comes before information. Information is really the translation and communication of data. When data is interpreted and processed to determine the true meaning, it then becomes useful and can be called Information.

10.What is data representation? DR refers to the form in which data is stored, processed, and transmitted. For exam. Devices such as PDAs, IPods, and comps store numbers, text, music, photos and videos in formats that can be handled by electronic circuitry. Those formats are data representations, data can be represented using digital or analog methods.

11. What is ASCII? What are the alternatives to ASCII (other codes)? The American Standard Code for Information Interchange ASCII is a scheme originally based on the English alphabet that encodes 128 specified characters - the numbers 0-9, the letters a-z and A-Z, some basic punctuation symbols, some control codes that originated with Teletype machines, and a blank space - into the 7-bit binary integers .ASCII codes represent text in computers, communications equipment, and other devices that use text. An alternative to the 8-bit Extended ASCII code, called EBCDIC is usually used only by older, IBM mainframe computers.

12. How can bits be used to store images? Sounds?To work with images, they must be digitized. Images can be digitized by treating them as a series of colored dots. Each dot is assigned a binary number according to its color. Sound, such as music and speech, is characterized by the properties of a sound wave.

13.What are the names of ceramic carrier which the processor or integrated circuit is housed in? wires, transistors, capacitors, logic gates, resistors.

14. What is microprocessor? A microprocessor processes all the instructions given to the computer (for example, add two numbers, execute program instructions, or print documents). Physically, the microprocessor is a single chip known as an integrated circuit (IC). Each chip is made out of silicon and it contains millions of transistors packed onto a chip. The microprocessor is referred to as the Central Processing Unit (CPU). The job of a microprocessor is to execute a series of machine instructions. These instructions are procedures to carry out a task written in a form that the computer can understand.

15. What kind of measurements we use when we talk about processor performance? The rate at which instructions are processed is controlled by an internal clock, also known as the system clock. Measured in Hertz (cycle per second) 1 Hertz - one cycle per second Processor clock rate measured in MHz and GHz. Machines are compared based on their clock speed or number of instructions per second (IPS) or (MIPS today). This measure depends on both the number of cycles per second and the mix of instructions executed. Bandwidth- the volume of data that can be transmitted within a fixed amount of time between components in a computer system or through connections to other computers (bits per second (bps) or bytes per second (Bps)

17. A specification such as 2.66 GHz means that the microprocessor’s clock operates at a speed of 2.66 billion cycles per second. All other things being equal, a comp with 2.66 GHz processor is faster than a comp with 1.5 GHz processor or a 933MHz processor.

18. What is FSB? How it’s measured? FSB stands for front side bus, a term that refers to the circuitry that transports data to and from the microprocessor. A FSB moves data quickly and allows the processor to work at full capacity. In today’s comps, FSB speed is measured in MHz and ranges from 200MHz to 1250MHz.

19. What is word size? Does it depend on the size of registers in the ALU? Word size refers to the number of bits that a microprocessor can manipulate at one time. Word size is based on the size of registers in the ALU and the capacity of circuits that lead to those registers. A processor with a 32-bit word size, for exam has 32-bir registers, processes 32 bits at a time, and is referred to as a 32 bit processor. Today’s personal comps typically contain 32-bit or 64-bit processor.

21. What is fetch-execute cycle? There are four steps that the CPU performs when executing an instruction; they are called the fetch-execute cycle . 1.Fetch - The control unit gets the instruction from memory.2. Interpret - The control unit decodes what the instruction means and directs the necessary data to be moved from memory to the ALU.3. Execute - The control unit directs the ALU to perform the necessary arithmetic or logic operations.4. Store - The result of the computation is stored in memory.

22. What types of RAM you know? How we measure them? RAM (random access memory) is a temporary holding area for both data and instructions. It is also referred to as main memory. Measured by its memory capacity and latency. Capacityis the maximum number of bits or bytes that can be stored. The capacity of RAM is typically measured in gigabytes (GB). Latency is the delay between the time when the memory device receives an address and the time when the first bit of data is available from the memory device. This delay is also referred to as access time (nanoseconds (ns), billionth of a second (10-9 sec). DRAM - Dynamic RAMwas a common type of RAM. Made of an integrated circuit (IC), composed of millions of transistors and capacitors. Capacitor holds electrons. An empty capacitor represents a zero, and a non-empty capacitor represents a one. The transistor is like a switch that controls whether the capacitor's state (charged or not charged, 1 or 0) is to be read or changed. SDRAM(Synchronous Dynamic RAM) Used in many personal computers Fast and relatively inexpensive Synchronized to the clockso that data can be sent to the CPU at each tick of the clock, increasing the number of instructions the processor can execute within a given time. DDR SDRAM (Double Data Rate SDRAM). Transfers twice the amount of data per clock cycle compared to SDRAM. Capacity is bigger than in SDRAM. RDRAM (Rambus Dynamic RAM) Higher bandwidth than SDRAM. More expensive compared to SDRAM. Enhances the performance of applications that access large amounts of data through memory, i.e. real-time video and video editing Used in PlayStation 2 and PlayStation3. SRAM (Static RAM) Uses transistors to store data.Because SRAM does not use capacitors, reading data from SRAM does not require recharging the capacitors. Therefore, it is faster than DRAM. Holds fewer bits and costs more compared to DRAM of the same size

23. What are the standards for expansion slots? The two most common types of expansion slots are Peripheral Component Interconnect (PCI) and Accelerated Graphics Port (AGP). PCI (Peripheral Component Interconnect )slot. Can hold a variety of expansion cards such as a sound card or an Ethernet card (PCI Express) AGP (Accelerated Graphics Port)slot. Primarily used for graphics cards . PCMCIA (personal computer memory card international association) slot. Used for laptops in place of PCI slots. Relatively smaller than a PCI slot. AMR or CNR – for sound cards and internal modems. ISA – old outdated slot

24. Why we need cache on processor? Another component of the microprocessor is the cache, a special high-speed memory that stores most recently used data in order to speed up the process of instruction execution. A cache can speed up data retrieval because recently used data is likely to be used again by the computer. Level 1 (L1) cache memoryor primary cache memory is located on the CPU to provide the CPU with the fastest access to data. There is also a slower cache, the Level 2 (L2) cache memory or secondary cache, located between the RAM and the CPU (sometimes on the CPU). If data cannot be found on either cache, it will be retrieved from RAM. Relative to the physical distance between the CPU and storage areas for data and instructions, data is retrieved more quickly from the L1 cache, then the L2 cache, and then the RAM.

25. What technology HyperTransport does? HyperTransport™ Technology is a high-speed, low latency, point-to-point link designed to increase the communication speed between integrated circuits in computers, servers, embedded systems, and networking and telecommunications equipment up to 48 times faster than some existing technologies. HyperTransport Technology helps reduce the number of buses in a system, which can reduce system bottlenecks and enable today's faster microprocessors to use system memory more efficiently in high-end multiprocessor systems.

26. What is benchmarking test? Different machines, however, should be compared by executing a standard suite of instructions with execution times carefully measured and recorded. This is a more careful way to measure machine performance, and it is known as benchmarking_ comparing disparate systems or components via a standardized set of instructions or series of tasks. Benchmarking can test anything from just the processor to executing office applications. The comparison is measured by the time it takes to execute these instructions. For example, Intel benchmarks its Pentium III processors based on the processors' performance of a variety of tasks, and so does Advanced Micro Devices with its processors. You can view various benchmark results comparing AMD and Intel processors. In general, it is good practice to ask which benchmarks are used in performance claims. For example, a benchmark that tests graphics speed may be irrelevant if the types of graphical applications you use are different from those used in the test. It is important to ensure that comparisons or claims are based on the same benchmarks. Benchmarking results by unbiased, independent organizations are especially useful.

27. What is ROM? CMOS? Read-only memory (ROM) - contains a set of instructions that is needed to start the computer. These instructions tell the computer how to access the hard disk, find the operating system, and load it into RAM. Types:Electrically Erasable Programmable Read-Only Memory (EEPROM) = Flash Memory CMOS (complementary metal oxide semiconductor) memory – stores permanently storage capacity, memory capacity (RAM), and display configurations (powered by a small battery)

28. What is EEPROM? a type of ROM, electrically erasable programmable read-only memory (EEPROM), can be updated by applying an electrical field changing instructions stored on the chip one byte at a time. EEPROM is a non-volatile chip that requires no power to hold data. EEPROMs replace CMOS technology that required power from a small battery integrated into the system board

29. What is digital audio? Digital audio is music, speech, and other sound represented in binary format for use in digital devices. Sound is produced by the vibration og matter such as a violin string or a drum head. This vibration causes pressure changes in the surrounding air creating waves.

30. What is sampling rate? Sampling rate refers to the number of times per second that a sound is measured during the recording process. It is expressed in hertz. One thousand samples per second is expressed as 1000Hz or 1KHz. Higher sampling rates increase the quality of the sound recording but require more storage space than lower sampling rates.

31. What is audio compression?Digital audio file size can be reduced using audio compression techniques. Audio compression reduces the size of a sound file by removing bits that represent extraneous noise and sound that are beyond the frequencies of normal hearing.

What is CD? DVD? Does it use the random access or sequential access? DVD Greater capacity, Narrower tracks. Use blue laser, which has a shorter wavelength than the red laser used by CDs, allowing it to focus on the tinier tracks of the DVD. Use multiple layers of tracks. Blue laser beams can penetrate the plastic and focus at different depths Some are dual-layered- Two sets of tracks on one side of the disk, one beneath the other. - This doubles the capacity of one side of a DVD disk. A double layer double side (DLDS) DVD drive uses double layers and can read double-sided disks.- This gives it four times the capacity of a single layer single side (SLSS) drive. CD- is an optical disc used to store digital data. CD was developed by Philips and Sony in 1979. First musical CD was created in 1982 (ABBA). 70% of musical market. Two recordable formats, CD-R and CD-RW. Less expensive and have less capacity than a DVD. Many computers (desktops and laptops) today are equipped with CD-RWs and read-only DVD combo drives. Diameter - 12 centimeter. Capacity – 650MB, 700MB, 800MB, 900MB and more. Shape CD. Sony vice-president Norio Ohga suggested: “Extend the capacity to 74 minutes to accommodate to Ludwig van Beethoven's Symphony No. 9 from the 1951 Bayreuth Festival.

33. What is serial processing? What is pipelining? What is parallel processing? Some processors execute instructions “serially”- that is, one instruction at a time. With serial processing, the processor must complete all steps in the instruction cycle before it begins to execute the next instruction. However, using a technology called pipelining, a processor can begin executing an extraction before it completes the previous instruction. Many of today’s microprocessors also perform parallel processing, in which multiple instructions are executed at the same time.

34. What is Hyper-Threading Technology?The abbreviation HT (or HTT), which appears in many computer ads, stands for HTT and refers to circuitry that enables a single processor to simulate two processors. HT speeds up some applications, but does not offer the performance boost of dual core technology.

35. What is overclocking? Overclocking is a technique for increasing the speed of a computer component, such as a processor, graphics card, system board, or memory. When successful, overclocking can increase the processing power of a slow component to match that of a faster, more expensive component. Overclocking is popular with gamers who want to squeeze every bit of processing speed out of their computers.

Data compression

Storing data in a format that requires less space than usual

When data is compressed, the file size shrinks.

Amount of shrinkage is referred as compression ratio.

Some compression techniques require specialized computer hardware.

Hardware or software used to compress and decompress is technically referred as codec (Compressor and Decompressor).

Disk compression

Disk compression shrinks the files and places it in a special volume on the hard disk (compressed volume file, CVF)

Disk volume is a disk or an area of a disk which has a unique name and is treated as a hard disk.

Disk compression creates a compressed volume containing data that has been re coded to use storage space more efficiently.

DriveSpace2, DriveSpace3, Stacker

Advantages :

– Gain storage space without any additional hardware.

– Under optimal circumstances, the hard disk capacity is doubled.

Disadvantages:

– If the compressed files are no longer required, drive space should be sufficient to hold the uncompressed data.

– File error in the compressed volume means the loss of all the data in that volume.

File compression

Shrinks one or more into single smaller file.

Compressed file cannot be used until it is uncompressed.

WinRar and WinZip are popular shareware programs that compress and uncompress files.

Compressing a file is called Zipping.

Uncompressing a file is known as Unzipping.

Compressed file Formats use

– Lossy Compression

– Lossless Compression

Lossy Compression throws away some of the original data for the graphic

For Example: JPEG(Joint Photographic Experts Group)

Lossless Compression provides a way to reconstitute all of the original data in a graphics file.

A piece of data, such as an alphabet letter, may be represented using a sequence of binary digits- 0's and 1's. There are several types of codes used to represent character data. For example, using extended ASCII (America Standard Code for Information Interchange) code, the alphabet letter "a" can be represented using a series of eight binary digits, "01100001." Each binary digit is called a bit. And, eight bits is one byte. Extended ASCII code uses eight bits (or one byte) to represent input characters

Benchmarking is the process of running standardized tests upon differing configurations to determine the speed of components or software.

Benchmarking: comparing disparate systems or components via a standardized set of instructions or series of tasks.